John gkant



(No Model.)

J. GRANT.

ARTIFIGIAL'STONE PAVEMENT.

No. 319,575. Patented June 9,1885.

WITNESSES 6 of W INVEWTOR M W Attorney n, PKTERS. Pholoiilhognpher. Washingmn. n a

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JOHN GRANT, OF OMAHA, NEBRASKA.

ARTlFlClAL- STONE PAVEMENT.

SPECIFICATION forming part of Letters Patent No. 319,575, dated June 9, 1885.

Application filed November 29, 1884.

To all whom it may concern:

Be it known that I, J OHN GRANT, a citizen of the United States, residing at Omaha, in county of Douglas and State of Nebraska, have invented certain new and useful Improvements in Artificial-Stone Pavements, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to certain improvements in artificial-stone pavements and roadways; and it has for its object to provide improved means for forming the joints between the blocks or sections of the artificial stone as they are laid, so as to leave a line of partial separation between them, in order to allow for expansion and contraction, and thus prevent the breakage of the finished pavement or roadway. This object I attain by the means hereinafter specified, and illustrated in the accompanying drawings, in which Figure 1 represents a perspective view of a pavement or roadway prepared to receive my improved compound; Fig. 2, a sectional view showing the pavement complete; and Fig. 3 represents a modification thereof.

In carrying out my invention I first take hard, clean furnace-slag and crush or roll it until itis broken up into fragments of less than half a square inch. These fragments are then run over a screen of ten meshes to the inch, or thereabout, in order to separate the finer particles or dust. I then take limestone or carbonate of lime and crush or break it until the fragments are of about the same size as the slag before mentioned, and screen the same in a similar manner, to separate small particles and dust. I then take one-half part of slag, onefourth part of limestone, one-fourth part of clean sharp sand, andmix the whole thoroughly. To this I add one part of Portland or other hydraulic cement, and mix with the whole sufficient water to bring the mass to a plastic state, in which condition it is ready to be laid.

In laying my improved compound I first excavate the earth to about fourteen inches below the surface of the intended pavement.

(No specimens.)

I then ram or roll the earth until a solid foundation is formed. Upon this I fill in about ten inches of broken brick, old plaster, coalashcs, or sand, or any or all of the same, so as to give a good drainage. This is also evenly and compactly rammed or rolled. I then take timbers of from four by four or four by two inches in cross-section, and set them at intervals of such distance as to leave spaces corresponding to the width of the stones, blocks, or sections to be laid. I then place against the sides of the timbers thin strips of wood, which rest upon the bottom of the bed and reach nearly to the top of the timbers or to the top of the base or lower section of the pavement when finished. I then fill in between the timbers to about the extent of three inches in depth a base composition consisting of four parts of gravel and one part of Portland cement, with sufficient water to render it plastic. I then allow the mass to harden, after which I remove the timbers, leaving the base ready for the surface-coatin g. Upon this I lay the surface composition of slag, lime- .stone, sand, and hydraulic cement, finishing it off by ramming or rolling to harden and compact it. It will be seen that as thus constructed the base of the pavement is separated by a thin strip of wood, which is destructible or soon rots, leaving the intervening spaces free in order to allow the sections to expand and contract to the fullest extent during changes of temperature, and that as the dividing-strips do not reach to the surface of the pavement the pavement is made effectually water-proof, permitting comparatively little water to find its way to the substructure.

The surface of the pavement when laid may be marked or scored above the joints, if desired.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. An artificial pavement composed of a base of coarse material, an intermediate course or layer of finer material subdivided into blocks by strips of suitable material between said blocks, and a continuous upper wearingas described, above the line of strips, snbstanr0 surface of finer material, substantially as detially as and for the purposes herein set forth.

scribed. In testimony whereof I affix my signature in 2. An artificial pavement composed of a presence of two witnesses.

base of coarse material, an intermediate course or layer of finer material subdivided into JOHN GRANT blocks by strips of suitable material between Witnesses:

said blocks, and a continuous upper wearing- EDWIN L. YEWELL,

surface of finer material, scored or indented, J. JOE MCCARTHY. 

